The show explores the lives of a group of people, some of whom fought on the losing side of a civil war, who make a living on the fringes of society as part of the pioneer culture of their star system. In this future, the only two surviving superpowers, the United States and China, fused to form the central federal government, called the Alliance, resulting in the fusion of the two cultures. According to Whedon's vision, "nothing will change in the future: technology will advance, but we will still have the same political, moral, and ethical problems as today".[2]

Firefly premiered in the U.S. on the Fox network on September 20, 2002. By mid-December, Firefly had averaged 4.7 million viewers per episode and was 98th in Nielsen ratings.[3] It was canceled after eleven of the fourteen produced episodes were aired. Despite the relatively short life span of the series, it received strong sales when it was released on DVD and has large fan support campaigns.[4][5] It won a Primetime Emmy Award in 2003 for Outstanding Special Visual Effects for a Series. TV Guide ranked the series at No. 5 on their 2013 list of 60 shows that were "Cancelled Too Soon".[6]

The series takes place in the year 2517, on a variety of planets and moons. The TV series does not reveal whether these celestial bodies are within one star system, only saying that Serenity's mode of propulsion is a "gravity-drive". However, re-runs start with Book providing the following backstory:
"After the Earth was used up, we found a new solar system and hundreds of new Earths were terraformed and colonized. The central planets formed the Alliance, and decided all the planets had to join under their rule. There was some disagreement on that point. After the war, many of the Independents who had fought and lost drifted to the edges of the system, far from Alliance control. Out here, people struggle to get by with the most basic technologies. A ship would bring you work. A gun would help you keep it. A captain’s goal was simple: Find a crew. Find a job, Keep flying."[9]

The film Serenity makes clear that all the planets and moons are in one large system and production documents related to the film indicate that there is no faster-than-light travel in this universe. The characters occasionally refer to "Earth-that-was", and the film establishes that, long before the events in the series, a large population had emigrated from Earth to a new star system in generation ships:[10] "Earth-that-was could no longer sustain our numbers, we were so many". The emigrants established themselves in this new star system, with "dozens of planets and hundreds of moons", and many of these were terraformed. The terraforming process was only the first step in making a planet habitable, however, and the outlying settlements often did not receive any further support in the construction of their civilizations. This resulted in many of the border planets and moons having forbidding, dry environments, well-suited to the Western genre.

The show takes its name from the "Firefly-class" spaceship Serenity that the central characters call home. It resembles a firefly in general arrangement, and the tail section, analogous to a bioluminescent insectoid abdomen, lights up during acceleration. The ship was named after the Battle of Serenity Valley, where then-Sergeant Malcolm Reynolds and then-Corporal Zoe Alleyne were among the few survivors on the losing side. It is revealed in "Bushwhacked" that the Battle of Serenity Valley is widely considered to have sealed the fate of the Independents.

Throughout the series, the Alliance is shown to govern the star system through an organization of "core" planets, following its success in forcibly unifying all the colonies under a single government. DVD commentary suggests that the Alliance is composed of two primary "core" systems, one predominantly Western in culture, the other pan-Asian, justifying the mixed linguistic and visual themes of the series. The central planets are firmly under Alliance control, but the outlying planets and moons resemble the 19th-century American West, under little governmental authority. Settlers and refugees on the outlying worlds have relative freedom from the central government, but lack the amenities of the high-tech civilization that exists on the inner worlds. In addition, the outlying areas of space ("the black") are inhabited by the Reavers, a cannibalistic group of nomadic humans that have become savage and animalistic.[11]

The captain of Serenity is Malcolm "Mal" Reynolds (Nathan Fillion) and the episode "Serenity" establishes that the captain and his first mate Zoe Washburne, née Alleyne (Gina Torres) are veteran "Browncoats" of the Unification War, a failed attempt by the outlying worlds to resist the Alliance's control. A later episode, "Out of Gas", reveals that Mal bought the spaceship Serenity to continue living beyond Alliance control. Much of the crew's work consists of cargo runs or smuggling. A main story arc centers on River Tam (Summer Glau) and her brother Simon (Sean Maher). River is a child prodigy, whose brain was subjected to experiments at the hands of Alliance scientists at a secret government institution. As a result, she displays symptoms of schizophrenia and often hears voices. It is later revealed that she is a "reader", one who possesses telepathic abilities. Simon gave up a career as a highly successful trauma surgeon in an Alliance hospital to rescue her, and they are both wanted fugitives. In the original pilot, "Serenity", Simon joins the crew as a paying passenger with River smuggled on board as cargo. As Whedon states in an episodic DVD commentary, every show he does is about creating family.[12] By the last episode, "Objects in Space", the fractured character of River has finally become whole, partly because the others decided to accept her into their "family" on the ship.[12]

The show blends elements from the space opera and Western genres, depicting humanity's future in a manner different from most contemporary science fiction programs in that there are no large space battles. Firefly takes place in a multi-cultural future, primarily a fusion of Western and East Asian cultures, where there is a significant division between the rich and poor. As a result of the Sino-American Alliance, Mandarin Chinese is a common second language; it is used in advertisements, and characters in the show frequently curse in Chinese. According to the DVD commentary on the episode "Serenity", this was explained as being the result of China and the United States being the two superpowers that expanded into space.[13]

The show also features slang not used in contemporary culture, such as adaptations of modern words, or new words altogether. For example, "shiny" is frequently used in a manner similar to the real world slang "cool", and "gorram" is used as a mild swear word. Written and spoken Chinese as well as Old West dialect are also employed. As one reviewer noted: "The dialogue tended to be a bizarre purée of wisecracks, old-timey Western-paperback patois, and snatches of Chinese".[4]

Tim Minear and Joss Whedon pointed out two scenes that, they believed, articulated the mood of the show exceptionally clearly.[12] One scene is in the original pilot "Serenity", when Mal is eating with chopsticks and a Western tin cup is by his plate; the other is in "The Train Job" pilot, when Mal is thrown out of a holographic bar window.[14] The DVD set's "making-of" documentary explains the distinctive frontispiece of the series (wherein Serenity soars over a herd of horses) as Whedon's attempt to capture "everything you need to understand about the series in five seconds".

One of the struggles that Whedon had with Fox was the tone of the show, especially with the main character Malcolm Reynolds. Fox pressured Whedon to make Mal more "jolly", as they feared he was too dark in the original pilot, epitomized by the moment he suggests he might "space" Simon and River, throwing them out of the airlock to die. In addition, Fox was not happy that the show involved the "nobodies" who "get squished by policy" instead of the actual policy makers.[12][15]

Firefly maintained an ensemble cast that portrayed nine crew members and passengers of the ship, Serenity. These characters fight criminals and schemers, Alliance security forces, the utterly psychotic and brutal Reavers, and the mysterious men with "hands of blue"—who are apparently operatives of a secret agency which is part of the megacorporation referred to in the DVD commentary only as The Blue Sun Corporation. The crew is driven by the need to secure enough income to keep their ship operational, set against their need to keep a low profile to avoid their adversaries. Their situation is greatly complicated by the divergent motivations of the individuals on board Serenity, but complex characterization was hampered by the show's brief run.

All nine of the main characters appeared in every episode, with the exception of "Ariel", from which Book is absent—he was meditating at an abbey.

Nathan Fillion as Malcolm "Mal" Reynolds – the owner and captain of Serenity and former Independent sergeant in the pivotal Battle of Serenity Valley. Malcolm grew up on a ranch, and was raised by his mother and the ranch hands. In the Unification War, he fought as a platoon sergeant in the 57th Overlanders of the Independent Army, the "Browncoats". He is cunning, a capable leader and a skilled fighter. Mal's main motivation is his will for independence. While he is not above petty theft, smuggling or even killing to maintain his free lifestyle, he is generally honest in his dealings with others, fiercely loyal to his crew and closely follows a personal moral code. He is openly antagonistic toward religion as a result of his war experience.

Gina Torres as Zoe Alleyne Washburne – second-in-command onboard Serenity, a loyal wartime friend of Captain Reynolds, and Wash's wife. Her surname during the Unification War was Alleyne.[16] She was born and raised on a ship[17] and served under Mal during the war as a corporal.[18] Described by her husband as a "warrior woman", she is a capable fighter who keeps calm even in the most dangerous situations. She demonstrates an almost unconditional loyalty to Mal, the only exception noted being her marriage to Wash, which the captain claims was against his orders.

Alan Tudyk as Hoban "Wash" Washburne – Serenity's pilot and Zoe's husband. Deeply in love with his wife, Wash expresses jealousy over his wife's "war buddy" relationship and unconditional support of their captain, most particularly in the episode "War Stories", in which he confronts Mal, even as they are being tortured by a dissatisfied customer. He joined pilot training just to see the stars, which were invisible from the surface of his polluted homeworld, and he joined Serenity despite being highly sought after by other ships. He is very light-hearted and tends to make amusing comments, despite the severity of any situation.

Morena Baccarin as Inara Serra – a Companion, which is the 26th century cross between a geisha and an escort or mistress, who rents one of Serenity's two small shuttles. Inara enjoys high social standing. Her presence confers a degree of legitimacy and social acceptance the crew of Serenity would not have without her on board. Inara displays great dignity, civility and compassion. There is strong romantic tension between her and Mal, who share many character traits, but each jokingly objects to the other's work as "whoring" or "petty theft", respectively. Both refuse to act on their feelings and try to keep their relationship professional.

Adam Baldwin as Jayne Cobb – a mercenary. He and Mal met when they were on opposite sides of a dispute; Mal, while held at gunpoint, offered Jayne his own bunk and a higher cut than his current employer, so Jayne switched sides and shot his then-partners. In the original pilot, "Serenity", he intimates to Mal that he did not betray him because "The money wasn't good enough." However, previously he had pointedly asked the Alliance agent whether he would be required to turn on the captain to help him, and in "Ariel" defends his actions in alerting the authorities regarding Simon and River by claiming he had not intended to betray Mal. He is someone who can be depended on in a fight.[19] He tends to act like a "lummox" who thinks he is the smartest person in space, but occasional hints of intelligence peek through this façade, giving the impression that he acts dumber than he is.[12] As Whedon states several times, Jayne is the man who will ask the questions that no one else wants to.[20] Even though he is a macho character, he has shown a particularly intense fear of Reavers, more so than the rest of the crew. Despite his amoral mercenary persona, he sends a significant portion of his income to his mother, again suggesting that there is more to his character than what he presents to the rest of the crew.

Jewel Staite as Kaywinnet Lee "Kaylee" Frye[21][22] – the ship's mechanic. In the episode "Out of Gas", it is established that she has no formal training, but keeps Serenity running with an intuitive gift for the workings of mechanical equipment. Jewel Staite explains Kaylee's character as being wholesome, sweet, and "completely genuine in that sweetness", adding "She loves being on that ship. She loves all of those people. And she is the only one who loves all of them incredibly genuinely."[23] She has a crush on Dr. Simon Tam. Kaylee is the heart of the ship: according to creator Joss Whedon, if Kaylee believes something, it is true.[12]

Sean Maher as Dr. Simon Tam – a trauma surgeon of the first caliber (top 3% in his class at a top core-planet institution), who is on the run after breaking his sister River out of a government research facility. In the episode "Safe", it is revealed that he and River had a privileged upbringing with access to the best education. In rescuing River over his stern father's severe objections, Simon sacrificed a highly successful future in medicine. His bumbling attempts at a romantic relationship with Kaylee are a recurring subplot throughout the series, and at every turn he seems to find a way to unwittingly foil his own attempts at romance. His life is defined by caring for his sister.[12]

Summer Glau as River Tam – smuggled onto the ship by her brother. She is a highly intelligent, compassionate and intuitive child prodigy. Experiments and invasive brain surgery at an Alliance secret facility left her delusional, paranoid, and at times violent, though her uncanny ability to seemingly sense things before they happen leaves questions as to where the delusions end and reality begins for her. The experiments seemed to have made her a psychic. The experiments also gave her a seemingly innate ability in hand-to-hand combat, and she is capable of killing or incapacitating several opponents with ease. She gets frequent fits of anxiety and experiences post-traumatic flashbacks of her time in the Alliance facility. Her mental instability and uncanny abilities, paired with several erratic and violent acts, are a recurring source of fear and doubt among the crew, especially with Jayne, whom she once slashed with a knife. Jayne very frequently requests that River and Simon be taken off the ship.

Ron Glass as Derrial Book – a Shepherd (equivalent to a pastor). Although presented as a devout Christian,[24] Book has profound, unexplained knowledge about criminal activities, police corruption, and military strategy, tactics, and weapons. In "Safe", he was shown to have sufficient status in the Alliance to receive emergency medical treatment from an Alliance ship, with no questions asked. He is also proficient in hand-to-hand combat and the use of firearms. While objecting to violence most of the time, on a rescue mission he joins the fight, stating that while the Bible is quite specific about killing, it is "somewhat fuzzier on the subject of kneecaps". Book is a moral guide for Mal and the rest of the crew, a voice of reason, conscience and spirituality. At the same time, he seems to get along well with the amoral mercenary Jayne, with the two spotting each other while working out using a bench press. His hidden backstory would have been gradually revealed, had the series continued, but was instead explored in the 2010 comic book The Shepherd's Tale.

Despite the series' short run, several recurring characters emerged from the inhabitants of the Firefly universe:

Mark Sheppard as Badger – an established smuggling middleman on the planet Persephone. He provided jobs for Serenity on at least two occasions. In the DVD commentary for the episode "Serenity", it was revealed that this part was originally written with the intention of Whedon himself playing the part. Badger appeared in the original pilot "Serenity" and in "Shindig", with a return in the comic book series Serenity: Those Left Behind.

Michael Fairman as Adelai Niska – a criminal kingpin who has a reputation for violent reprisals, including severe, prolonged torture, against those who fail him or even irritate him. He appeared in "The Train Job" and "War Stories".

Christina Hendricks as "Saffron" – a con artist whose real name is unknown. She first appeared in the episode "Our Mrs. Reynolds" as Mal's involuntarily acquired wife. She has a habit of marrying her marks during her scams. She returns in episode "Trash", where Mal jokingly addresses her as "YoSaffBridge", from the three of her aliases known within the show: "Yolanda", "Saffron", and "Bridget".

Jeff Ricketts and Dennis Cockrum as "The Hands of Blue" – two anonymous men wearing suits and blue gloves who pursue River, apparently to return her to the institute from which she escaped, as shown in "The Train Job", "Ariel", and the Serenity: Those Left Behind comic. They kill anyone, including Alliance personnel, who had contact with her, using a mysterious hand-held device that causes fatal hemorrhaging in anyone at whom it is aimed. River, during anxiety attacks or psychological meltdowns, has repeated the phrase "Two by two/hands of blue" in a way that resembles poetic meter. This suggests that River has had close experience(s) with them.

Captain Malcolm "Mal" Reynolds and his crew aboard Serenity illegally salvage goods from a derelict ship. However, because the goods are marked by the Alliance, and an Alliance ship spotted an out-dated Firefly-class freighter leaving the scene, Mal's fence Badger refuses to handle the goods. Mal has to sell elsewhere. To make extra money, the crew picks up passengers: Shepherd Book, Dr. Simon Tam and Lawrence Dobson. En route to the new buyer, Patience, Dobson turns out to be an Alliance federal agent tracking Simon. Dobson attempts to arrest Simon, but is himself taken prisoner. Simon reveals that his genius sister River Tam, hidden in his luggage, was experimented on by the Alliance and that he is trying to smuggle her to safety. Patience attempts to rob Mal, but Mal takes the payment after a shootout. Lawrence escapes and holds River hostage, but Mal shoots him. Mal offers Simon and River safe haven aboard Serenity.

Crime lord Adelai Niska hires the crew to rob a train of unspecified goods. The crew is able to transfer the goods to Serenity flying above, but Mal and Zoe Washburne are forced to stay behind on the train. They learn that they have stolen medicine desperately needed by the locals. The crew argue whether they should deliver the goods to Niska. Ultimately, they decide to rescue Mal and Zoe first through subterfuge. Mal decides to return the medicine. However, Niska's thugs track them down. After killing some of them and capturing the rest, Mal and Zoe take the medicine to those in need of it and refund Niska's money.

The crew discover a derelict ship that was attacked by Reavers and takes aboard the sole survivor (Branden R. Morgan). Shortly after, an Alliance cruiser orders Serenity to dock to it. Simon and River hide to avoid capture. The rest of the crew are interrogated. Refusing to believe in the existence of Reavers, the Alliance's Commander Harken (Doug Savant) decides that the crew will be charged with attacking the ship and murdering its settler passengers. However, the survivor kills some of the Alliance crew and escapes back to Serenity. Mal convinces Harken to let him help find the survivor. Mal kills the survivor, saving Harken's life in the process, and the crew is released.

Inara Serra is hired by Atherton Wing, one of her regular clients, and accompanies him to a formal dance. Badger hires Mal to meet a contact at the same dance and try to set up a smuggling job. When Mal hits Atherton for the way he treats Inara, Mal finds he has unknowingly challenged Atherton to a duel with swords. Atherton is a skilled swordsman and duelist. Inara tries to teach Mal how to use a sword overnight. Despite all expectations, Mal wins the duel. The contact, who personally dislikes Atherton, agrees to hire the crew to smuggle cattle to the Rim.

The crew delivers cattle to the Rim, but Book is gravely injured when they are stuck in the middle of a shootout. At the same time, Simon and River Tam are kidnapped by locals while sightseeing in town. Mal chooses to leave the Tams behind to seek help for Book. Desperate, they turn to an Alliance ship. At first hostile, the Alliance officer they speak to provides medical aid after seeing Book's ID. Meanwhile, the kidnappers belong to a community in desperate need of a real doctor, and Simon tentatively hopes he has found a haven for himself and River. However, the religious residents come to believe River is a witch and attempt to burn her at the stake. Serenity returns just in time to rescue the siblings. When Simon asks Mal why he came back, the captain tells Simon that he and River are part of the crew.

After completing a job for a small settlement, during the ensuing celebration, Mal learns that he inadvertently married a young woman called Saffron, part of the payment. Although Mal insists they are not married, Saffron is determined to fulfill the role of a subservient wife. Saffron is not what she appears to be, however. She later knocks Mal out, locks the ship into a course for murderous ship scrappers, and flees in a shuttle. The crew barely escapes.

The crew lands on a planet to meet a contact. Although Jayne Cobb insists he is wanted there, they are dumbfounded to learn that he is revered by the locals as a folk hero. Mal attempts to use Jayne's status as a distraction to move smuggled goods across town. However, Magistrate Higgins releases Jayne's former accomplice Stitch Hessian, whom Jayne abandoned years ago during a botched robbery and now seeks revenge. Stitch publicly confronts Jayne, revealing what the townspeople believe happened to be false. Stitch shoots, but a villager jumps in front of Jayne and dies. Jayne kills Stitch and urges the townspeople to stop viewing him as a hero. Serenity is "land-locked" at Higgins' order to try to capture Jayne. Higgins' 26-year-old son Fess (Zachary Kranzler), encouraged by Inara to stand up for himself after he loses his virginity to her, as paid for by Higgins, orders the unlocking of the ship, and Serenity departs.

An explosion in the engine room leaves Serenity with the engine and the life support system and its backup all out of commission. With only a few hours of oxygen left, Mal has the crew leave in the two shuttles while he remains aboard and hopes to contact a passing ship. In a series of flashbacks, Mal convinces Zoe, Jayne, Inara, Hoban Washburne, and Kaylee Frye to join his crew. Back in the present, Mal is able to hail a ship and secure the part needed to fix the engine, though he is shot by another crew when they prove to have less than pure motives. Mal's crew returns to Serenity in time to save his life.

While waiting on the Core planet Ariel, Simon hires the crew to help him smuggle River into a local hospital for a thorough diagnostic. In return, he will tell them how to loot the hospital for valuable medicine. Once inside, Jayne attempts to turn in Simon and River for the reward. However, the Alliance officer arrests Jayne as well in order to keep the bounty for himself. The crew escapes, but Mal realizes that Jayne betrayed Simon and River. Mal arranges for Jayne to suffocate when Serenity leaves the planet's atmosphere, but then lets him live.

Angry that Zoe and Mal have an unshakeable bond as war veterans, her husband Wash demands to take her place on a seemingly routine mission. Mal begrudgingly allows Wash to go along. They are captured by Niska, out to restore his reputation after they failed to complete the robbery he commissioned in "The Train Job". Zoe has only enough money to ransom one of them. She unhesitatingly chooses Wash. The crew band together to rescue Mal.

When Saffron crosses paths with Mal again, she asks him to help her rob an extremely valuable antique weapon from a wealthy man. Once Mal and Saffron are inside, they are discovered, and it is revealed that the man is married to Saffron. Although the man seems initially oblivious, he is aware of Saffron's true nature and called the authorities. Mal and Saffron escape, but Saffron betrays Mal, stranding him naked in the desert, and tries to pick up the weapon. However, Inara gets there first. She leaves Saffron locked up in a storage container for the authorities, and the crew escapes with the weapon.

Mal and Zoe receive in the mail the body of Tracey, a comrade-in-arms who fought with them at the Battle of Serenity Valley, and they attempt to honor his recorded wish to be returned home. However, a corrupt Alliance officer demands they turn over the body and the goods the soldier was smuggling. While searching the body for clues, they learn that Tracey is still alive and is smuggling organs. Tracey had double crossed his employers, but they killed his new buyer. Mal is ultimately forced to kill him to protect the crew, and Book blackmails the officer into leaving. Mal and Zoe take Tracey's body home to his family.

Nandi, Inara's friend and a former Companion, asks her for help: she needs to defend her brothel from Ranse Burgess, a powerful man who impregnated Petaline, one of her employees. He is determined to take the baby once it is born. Mal and Nandi have sex the night before the battle; when Inara finds out, she is deeply hurt. The crew successfully defends the brothel, but Burgess kills Nandi before being captured. Petaline shows Burgess his newborn son, then shoots him. Afterward, Inara tells Mal that she has decided to leave the ship.

River picks up a gun she finds in the cargo bay (which she sees as a tree branch), frightening the crew into wondering if she is too dangerous to be let loose. Bounty hunterJubal Early sneaks aboard the ship in flight, incapacitates some of the crew and captures Simon. River agrees to go with Early in exchange for leaving her brother and the ship in peace. However, she orchestrates a plan to dispose of Early. Mal confirms her place as a member of the crew.

Whedon developed the concept for the show after reading The Killer Angels, the Pulitzer Prize-winning novel by Michael Shaara chronicling the Battle of Gettysburg during the American Civil War. He wanted to follow people who had fought on the losing side of a war and their experiences afterwards as pioneers and immigrants on the outskirts of civilization, much like the post-American Civil War era of Reconstruction and the American Old West culture.[25] He intended the show to be "a Stagecoach kind of drama with a lot of people trying to figure out their lives in a bleak pioneer environment".[26] Whedon wanted to develop a show about the tactile nature of life, a show where existence was more physical and more difficult.[12] After reading The Killer Angels, Whedon read a book about Jewish partisan fighters in World War II that also influenced him.[25] Whedon wanted to create something for television that was more character-driven and gritty than most modern science fiction. Television science fiction, he felt, had become too pristine and rarefied.[27]

Whedon wanted to give the show a name that indicated movement and power, and felt that "Firefly" had both. This powerful word's relatively insignificant meaning, Whedon felt, added to its allure. He eventually wound up creating the ship in the image of a firefly.[12]

During filming of the pilot episode, Whedon was still arguing with Fox that the show should be displayed in widescreen format. Consequently, he purposely filmed scenes with actors on the extreme edge of both sides so that they could only be shown in widescreen.[12] This led to a few scenes on the DVD (and later Blu-ray) where objects or setups that were not visible in the original 4:3 broadcasts were now displayed—such as the scene in the pilot where Wash mimes controlling the ship with a non-existent yoke. However, the pilot was rejected by the Fox executives, who felt that it lacked action and that the captain was too "dour".[14] They also disliked a scene in which the crew backed down to a crime boss, since the scene implied the crew was "being nothing".[12] Thus, Fox told Whedon on a Friday afternoon that he had to submit a new pilot script on Monday morning or the show would not be picked up.[14] Whedon and Tim Minear closeted themselves for the weekend to write what became the new pilot, "The Train Job".[14] At the direction of Fox, they added "larger than life" characters[14][15] such as the henchman "Crow", and the "hands of blue" men, who also introduced an X-Files-type ending.[15]

For the new pilot, Fox made it clear that they would not air the episodes in the widescreen format. Whedon and company felt they had to "serve two masters" by filming widescreen for eventual DVD release, but keeping objects in frame so it could still work when aired in pan and scanfull frame.[28] To obtain an immersive and immediate feel, the episodes were filmed in a documentary style with hand-held cameras, giving them the look of "found footage", with deliberately misframed or out-of-focus subjects.[12][29] As Whedon related: "...don't be arch, don't be sweeping—be found, be rough and tumble and docu[mentary] and you-are-there".[30]Computer-generated scenes mimicked the motion of a hand-held camera. This style was not used, however, when shooting scenes that involved the central government, the Alliance. Tracking and steady cameras were used to show the sterility of this aspect of the Firefly universe.[12] Another style employed was lens flares harking back to 1970s television. This style was so desired that the director of photography, David Boyd, sent back the cutting-edge lenses which reduced lens flare in exchange for cheaper ones.[12]

Unlike most other science fiction shows, which add sound to space scenes for dramatic effect, Firefly portrays space as silent, because sounds cannot be transmitted in the vacuum of space.[31]

The spacecraft Serenity was digitally rendered by special effects house Zoic Studios. The shape was inspired by the shape of the firefly insect, and its tail section lights up in imitation of it.

Production designer Carey Meyer built the ship Serenity in two parts (one for each level) as a complete set with ceilings and practical lighting installed as part of the set that the cameras could use along with moveable parts.[29][32] The two-part set also allowed the second unit to shoot in one section while the actors and first unit worked undisturbed in the other. As Whedon recalled: "...you could pull it away or move something huge, so that you could get in and around everything. That meant the environment worked for us and there weren't a lot of adjustments that needed to be made."[32] There were other benefits to this set design. One was that it allowed the viewers to feel they were really in a ship.[29] For Whedon, the design of the ship was crucial in defining the known space for the viewer, and that there were not "fourteen hundred decks and a holodeck and an all-you-can-eat buffet in the back".[33] He wanted to convey that it was utilitarian and that it was "beat-up but lived-in and ultimately, it was home".[34] As Joss Whedon discusses in the DVD commentary, each room represented a feeling or character, usually conveyed by the paint color.[33] He explains that as you move from the back of the ship in the engine room, toward the front of the ship to the bridge, the colors and mood progress from extremely warm to cooler. Besides evoking a mood associated with the character who spends the most time in each area, the color scheme also alludes to the heat generated in the tail of the ship.
Whedon was also keen on utilizing vertical space; thus, having the crew's quarters accessible by ladder was important.[32] Another benefit of the set design was that it also allowed the actors to stay in the moment and interact, without having to stop after each shot and reset up for the next.[29] This helped contribute to the documentary style Whedon strove for.

The set had several influences, including the sliding doors and tiny cubicles reminiscent of Japanese hotels.[32] Artist Larry Dixon has noted that the cargo bay walls are "reminiscent of interlaced, overlapping Asian designs, cleverly reminding us of the American-Chinese Alliance setting while artistically forming a patterned plane for background scale reference".[35] Dixon has also remarked on how the set design contributed to the storytelling through the use of color, depth and composition, lighting, as well as its use of diagonals and patterned shadows.[35]

Their small budget was another reason to use the ship for much of the storytelling. When the characters did go off the ship, the worlds all had Earth atmosphere and coloring because they could not afford to design alien worlds. "I didn't want to go to Yucca Flats every other episode and transform it into Bizarro World by making the sky orange", recalled Whedon.[30] As Meyer recalled: "I think in the end the feel was that we wound up using a lot of places or exteriors that just felt too Western and we didn't necessarily want to go that way; but at some point, it just became the lesser of two evils—what could we actually create in three days?"[36]

Greg Edmonson composed the musical score for the series. He stated that he wrote for the emotion of the moment. However, one reviewer averred that he also wrote for the characters, stating: "Edmonson has developed a specialized collection of musical symbolism for the series".[40] To help illustrate the collection, the reviewer gave key leitmotifs, or "signatures", various names, noting that "Serenity" recalls the theme of the show and is used when they return to the ship, or when they were meeting clandestinely; it was "the sound of their home". The slide guitar and fiddle used in this piece are portable instruments which fit the lifestyle of the crew: "the music they make calls up tunes played out in the open, by people who were hundreds of miles away yesterday. 'Serenity' conjures the nomadic lifestyle the crew leads and underlines the western aspect of the show."[40] Another emotional signature was "Sad Violin". It was used at the end of the Battle of Serenity Valley, but also helped set up the joke for when Mal tells Simon that Kaylee is dead in the episode "Serenity". The most memorable use of "Sad Violin", however, is at the end of "The Message", when the crew mourned the death of Tracey. This was also the last scene of the last episode the actors shot, and so this was seen by them, and Edmonson, as Firefly's farewell. To denote impending danger, "Peril" was used, which is "a low pulse, like a heartbeat, with deep chimes and low strings".[40] The reviewer also noted character signatures. The criminal Niska has his own signature: Eastern European or Middle Eastern melodies over a low drone. Simon and River's signature was a piano played sparsely with a violin in the background. This is in contrast to the portable instruments of "Serenity": the piano is an instrument that cannot be easily moved and evokes the image of "the distant house and family they both long for". The various signatures were mostly established in the first pilot, "Serenity", and helped enhance the narrative.

In every episode, the musical score intensified my experience of this intelligent, remarkable show. Using and combining all these signatures, Greg Edmonson brought out aspects of Firefly's story and characters that were never explicitly revealed in the other elements of the series.[40]

Whedon's use of music in his television shows has been regarded as 'filmic', in that he has been argued to use it to remind viewers at 'pivotal moments' of earlier events, resulting in a tighter continuity throughout the season.[41]

The musical score expressed the cultural fusion depicted in the show. Cowboy guitar blended with Asian influence produced the atmospheric background for the series. As one reviewer stated:

Old music from the future—the music of roaring campfires and racous [sic] cowboys mixed with the warm, pensive sounds of Asian culture and, occasionally, a cold imperial trumpet, heralding the ominous structural presence of a domineering government. Completely thrilling.—Steve Townsley[42]

The show's theme song, "The Ballad of Serenity", was written by Joss Whedon and performed by Sonny Rhodes. Whedon wrote the song before the series was greenlit and a preliminary recording performed by Whedon can be found on the DVD release. The soundtrack to the series was released on CD on November 8, 2005, by Varèse Sarabande, although a 40-minute soundtrack was released by Fox Music in September 2005 as a digital EP.[39] "The Ballad of Serenity" was used by NASA as the wake-up song for astronaut Robert L. Behnken and the other crewmembers of STS-130 on February 12, 2010.[43]

Track listing[44](tracks 1–17 appear in both the digital and CD releases)

In casting his nine-member crew, Whedon looked first at the actors and considered their chemistry with others. Cast member Sean Maher recalls, "So then he just sort of put us all together, and I think it was very quick, like right out of the gate, we all instantly bonded".[45] All nine cast members were chosen before filming began. However, while filming the original pilot "Serenity", Whedon decided that Rebecca Gayheart was unsuitable for the role of Inara Serra, and shot her scenes in singles so that it would be easier to replace her.[12]Morena Baccarin auditioned for the role and two days later was on the set in her first television show. "Joss brought me down from the testing room like a proud dad, holding my hand and introducing me," Baccarin recalled.[46]

Whedon approached Nathan Fillion to play the lead role of Malcolm Reynolds; after Whedon explained the premise and showed him the treatment for the pilot, Fillion was eager for the role.[47] Fillion was called back several times to read for the part before he was cast. He noted that "it was really thrilling. It was my first lead, and I was pretty nervous, but I really wanted that part, and I wanted to tell those stories."[48] Fillion later said he was "heartbroken" when he learned the series had been cancelled. Fillion has called his time on Firefly the best acting job he ever had,[49] and compares every job he has had to it.[50]

Alan Tudyk applied through a casting office and several months later was called in for an audition, where he met with Whedon. He was called back to test with two candidates for the role of Zoe (Wash's wife) and was told that it was down to him and one other candidate. The Zoes he tested with were not selected (Gina Torres eventually received the role), and Tudyk was sent home but received a call informing him he had the part anyway.[51] His audition tape is included in the special features of the DVD release.

Sean Maher recalls reading for the part and liking the character of Simon Tam, but that it was Whedon's personality and vision that "sealed the deal" for him.[45] For the role of Simon's sister, River Tam, Whedon called in Summer Glau for an audition and test the same day. Glau had first worked for Whedon in the Angel episode "Waiting in the Wings". Two weeks later, Whedon called her to tell her she had the part.[55]

Veteran television actor Ron Glass has said that until Firefly, he had not experienced or sought a science-fiction or western role, but he fell in love with the pilot script and the character of Shepherd Book.[56]

Tim Minear was selected by Whedon to be the show runner, who serves as the head writer and production leader. According to Whedon "[Minear] understood the show as well as any human being, and just brought so much to it that I think of it as though he were always a part of it".[57] Many of the other production staff were selected from people Whedon had worked with in the past, with the exception of the director of photography David Boyd, who was the "big find" and who was "full of joy and energy".[58]

The writers were selected after interviews and script samplings. Among the writers were José Molina, Ben Edlund, Cheryl Cain, Brett Matthews, Drew Z. Greenberg and Jane Espenson.[58] Espenson wrote an essay on the writing process with Mutant Enemy Productions.[59] A meeting is held and an idea is floated, generally by Whedon, and the writers brainstorm to develop the central theme of the episode and the character development. Next, the writers (except the one working on the previous week's episode) meet in the anteroom to Whedon's office to begin 'breaking' the story into acts and scenes. For the team, one of the key components to devising acts is deciding where to break for commercial and ensuring the viewer returns. "Finding these moments in the story help give it shape: think of them as tentpoles that support the structure". For instance, in "Shindig", the break for commercial occurs when Malcolm Reynolds is gravely injured and losing the duel. "It does not end when Mal turns the fight around, when he stands victorious over his opponent. They're both big moments, but one of them leaves you curious and the other doesn't."

Next, the writers develop the scenes onto a marker-filled whiteboard, featuring "a brief ordered description of each scene". A writer is selected to create an outline of the episode's concept—occasionally with some dialogue and jokes—in one day. The outline is given to showrunner Tim Minear, who revises it within a day. The writer uses the revised outline to write the first draft of the script while the other writers work on developing the next. This first draft is usually submitted for revision within three to fourteen days; afterward, a second and sometimes third draft is written. After all revisions are made, the final draft would be produced as the 'shooting draft'.

Jill Ohanneson, Firefly's original costume designer, brought on Shawna Trpcic as her assistant for the pilot. When the show was picked up, Ohanneson was involved in another job and declined Firefly, suggesting Trpcic for the job.

The costumes were chiefly influenced by World War II, the American Civil War, the American Old West, and 1861 samurai Japan. Trpcic used deep reds and oranges for the main cast, to express a feeling of "home", and contrasted that with grays and cool blues for the Alliance.[60] Since the characters were often getting shot, Trpcic would make up to six versions of the same costume for multiple takes.[61]

For River, mostly jewel tones were used to set her apart from the rest of the Serenity crew. River had boots to contrast with the soft fabrics of her clothes, "because that's who she is—she's this soft, beautiful, sensitive girl, but with this hardcore inner character," recalled Trpcic.[62]

The designers also wanted to contrast Simon, River's brother, with the rest of the crew. Whereas they were dressed in cotton, Simon wore wool, stiff fabrics, satins and silk. He was originally the "dandy", but as the show progressed, he loosened up slightly.[63]

For Kaylee, Trpcic studied up on Japanese and Chinese youth, as originally the character was Asian. Other inspirations for Kaylee's costumes were Rosie the Riveter and Chinese Communist posters.[64]

Inara's costumes reflect her high status, and are very feminine and attractive.

Trpcic designed and created the clothes for the minor character of Badger with Joss Whedon in mind, since he intended to play that part. When Mark Sheppard played the role instead, he was able to fit into the clothes made for Whedon.[65]

For the Alliance, besides the grays and cool blues, Trpcic had in mind Nazi Germany, but mixed it with different wars, as the first sketches were "too Nazi".[66] The uniforms of the Alliance soldiers are from the 1997 film Starship Troopers.[67]

In the commentary for the pilot episode Whedon points out that "bad guys wear hats, good guys don't".

Since the cancellation of the series, various cast and crew members have revealed details they had planned for the show's future:[68][69]

Alan Tudyk had the idea for an episode about a planet that is always day on one side, and night on the other. On the night side, Jayne accidentally spills a type of pheromone on himself and the crew, which attracts a species of dogs. The crew are chased back to the ship by these dogs. There River uses her mind powers to domesticate the dogs.

Adam Baldwin wanted to make an episode in which Jayne goes up against Mal as captain of his own ship.

Tim Minear revealed the secret of Inara's syringe, as seen in the pilot episode; she is infected with a deadly disease. There would have been an episode where she is gang-raped by Reavers. Because she injected herself with the syringe, all of the Reavers on the ship die.

According to Nathan Fillion, there was an episode in which the crew land on a dying planet. The inhabitants try to steal Serenity, after they explain to the crew about their need to get off the planet. The problem is that unless they were to run into another ship along the way, with the extra passengers, Serenity would not have enough fuel and oxygen to make it to the closest destination. While everyone else is asleep, Mal takes the ship himself and discovers that help never would have arrived.

Firefly consists of a two-hour pilot and thirteen one-hour episodes (with commercials). The series originally premiered in the United States on Fox in September 2002. The episodes were aired out of the intended order. Although Whedon had designed the show to run for seven years,[70] low ratings resulted in cancellation by Fox in December 2002 after only 11 of the 14 completed episodes had aired in the United States.[71] The three episodes unaired by Fox eventually debuted in 2003 on the Sci Fi Channel in the United Kingdom.[72] Prior to cancellation, some fans, worried about low ratings, formed the Firefly Immediate Assistance campaign whose goal was to support the production of the show by sending in postcards to Fox. After it was canceled, the campaign worked on getting another network such as UPN to pick up the series.[73][74] The campaign was unsuccessful in securing the show's continuation.[5]

The A.V. Club cited several actions by the Fox network that contributed to the show's failure, most notably airing the episodes out of sequence, making the plot more difficult to follow.[75] For instance, the double episode "Serenity" was intended as the premiere, and therefore contained most of the character introductions and back-story. However, Fox decided that "Serenity" was unsuitable to open the series, and "The Train Job" was specifically created to act as a new pilot.[14] In addition, Firefly was promoted as an action-comedy rather than the more serious character study it was intended to be, and the showbiz trade paper Variety noted Fox's decision to occasionally preempt the show for sporting events.[71]

Fox remastered the complete series in 1080i high-definition for broadcast on Universal HD, which began in April 2008.[76]

On March 12, 2009, the series was the winner of the first annual Hulu awards in the category "Shows We'd Bring Back".[77]

The Science Channel began airing the series on March 6, 2011.[78] All episodes aired in the intended order, including episodes "Trash", "The Message" and "Heart of Gold", which were not aired in the original Fox series run. Along with each episode, Dr. Michio Kaku provided commentary about the real-life science behind the science fiction of the show.[79]

A box set containing the fourteen completed episodes (including those which had not yet aired in the United States) was released on region 1 DVD on December 9, 2003,[80] region 2 on April 19, 2004, and region 4 on August 2, 2004. The box features the episodes in the original order in which the show's producers had intended them to be broadcast, as well as seven episode commentaries, outtakes and other features. The DVDs feature the episodes as they were shot in 16:9 widescreen, with anamorphic transfers and Dolby Surround audio. By September 2005, its DVD release had sold approximately 500,000 copies.[81]

The series was re-released on Blu-ray Disc on November 11, 2008, comprising three discs; exclusive extras to the Blu-ray release include extra audio commentary from Joss Whedon, Nathan Fillion, Alan Tudyk and Ron Glass for the episode "Our Mrs. Reynolds", as well as an additional featurette, "Firefly" Reunion: Lunch with Joss, Nathan, Alan and Ron.[82]

Many reviews focused on the show's fusion of Wild West and outer space motifs. TV Guide's Matt Roush, for instance, called the show "oddball" and "offbeat", and noted how literally the series took the metaphor of space operas as Westerns. Roush opined that the shift from space travel to horseback was "jarring", but that once he got used to this, he found the characters cleverly conceived, and the writing a crisp balance of action, tension and humor.[84] Several reviewers, however, criticized the show's setting; Tim Goodman of the San Francisco Chronicle felt that the melding of the western and science fiction genres was a "forced hodgepodge of two alarmingly opposite genres just for the sake of being different" and called the series a "vast disappointment",[85] and Carina Chocano of Salon.com said that while the "space as Wild West" metaphor is fairly redundant, neither genre connected to the present.[86] Emily Nussbaum of the New York Times, reviewing the DVD set, noted that the program featured "an oddball genre mix that might have doomed it from the beginning: it was a character-rich sci-fi western comedy-drama with existential underpinnings, a hard sell during a season dominated by Joe Millionaire".[87]

The Boston Globe described Firefly as a "wonderful, imaginative mess brimming with possibility". The review further notes the difference between the new series and other programs was that those shows "burst onto the scene with slick pilots and quickly deteriorate into mediocrity... Firefly is on the opposite creative journey."[88] Jason Snell called the show one of the best on television, and one "with the most potential for future brilliance".[89]

Reviewers also compared Firefly to Whedon's other series, Buffy the Vampire Slayer. Chocano noted that the series lacks the psychological tension of Buffy, and suggests that this might be attributable to the episodes being aired out of order.[86]MSN, on the other hand, pointed out that after viewing the DVD boxed set it was easy to see why the program had attracted many die-hard fans. "All of Whedon's fingerprints are there: the witty dialogue, the quirky premises and dark exploration of human fallacy that made Buffy brilliant found their way to this space drama".[90]

Example fan artwork produced by Susan Renee Tomb (widely known in the Browncoat community as "11th Hour") used as guerrilla marketing to promote sale of Firefly and Serenity DVDs.

Firefly generated a loyal base of fans during its three-month original broadcast run on Fox in late 2002. These fans, self-styled Browncoats, used online forums to organize and try to save the series from being canceled by Fox only three months after its debut. Their efforts included raising money for an ad in Variety magazine and a postcard writing campaign to UPN.[73][74] While unsuccessful in finding a network that would continue the show, their support led to a release of the series on DVD in December 2003.[5] A subsequent fan campaign raised over $14,000 in donations to have a purchased Firefly DVD set placed aboard 250 U.S. Navy ships by April 2004 for recreational viewing by their crews.[91]

These and other continuing fan activities eventually persuaded Universal Studios to produce a feature film, Serenity.[4] (The title of Serenity was chosen, according to Whedon, because Fox still owned the rights to the name 'Firefly'). Numerous early screenings of rough film cuts were held for existing fans starting in May 2005 as an attempt to create a buzz to increase ticket sales when the final film cut was released widely on September 30, 2005.[4] The film was not as commercially successful as fans had hoped, opening at number two and making only $40 million worldwide during its initial theatrical release.

On June 23, 2006, fans organized the first worldwide charity screenings of Serenity in 47 cities, dubbed as Can't Stop the Serenity or CSTS, an homage to the movie's tagline, "Can't stop the signal".[92] The event raised over $65,000[93] for Whedon's favorite charity, Equality Now. In 2007, $106,000 was raised;[94] in 2008, $107,219; and in 2009, $137,331.[95]

In July 2006, a fan-made documentary was released, titled Done the Impossible, and is commercially available. The documentary relates the story of the fans and how the show has affected them, and features interviews with Whedon and various cast members.[96] Part of the DVD proceeds are donated to Equality Now.

A fan-made, not-for-profit, unofficial sequel to Serenity, titled Browncoats: Redemption, premiered at Dragon*Con 2010 on September 4, 2010. According to the film's creator and producer, Whedon gave "his blessing" to the project. The film was sold on DVD and Blu-ray at the film's website, with all proceeds being distributed among five charities.[102][103] The film was also screened at various science-fiction conventions across the United States, with admission receipts similarly being donated. All sales ended on September 1, 2011, one year after its premiere, with total revenues exceeding $115,000.[104]

In 2005, New Scientist magazine's website held an internet poll to find "The World's Best Space Sci-Fi Ever". Firefly came in first place, with its cinematic follow-up Serenity in second.[105] In 2012, Entertainment Weekly listed the show at No. 11 in the "25 Best Cult TV Shows from the Past 25 Years," commenting, "as it often does, martyrdom has only enhanced its legend."[106]

Brad Wright, co-creator of Stargate SG-1 has said that the 200th episode of SG-1 is "a little kiss to Serenity and Firefly, which was possibly one of the best canceled series in history". In the episode, "Martin Lloyd has come to the S.G.C. [Stargate Command] because even though 'Wormhole X-Treme!' was canceled after three episodes, it did so well on DVD they're making a feature [film]".[107] The follow-up film, Serenity, was voted the best science fiction movie of all time in an SFX magazine poll of 3,000 fans.[108]Firefly was later ranked #25 on TV Guide's Top Cult Shows Ever.[109] The name for the Google beta app Google Wave was inspired by this TV series.[110]

In an interview on February 17, 2011, with Entertainment Weekly, Nathan Fillion joked that: "If I got $300 million from the California Lottery, the first thing I would do is buy the rights to Firefly, make it on my own, and distribute it on the Internet".[79] This quickly gave rise to a fan-run initiative to raising the funds to purchase the rights.[111] On March 7, 2011, the organizers announced the closure of the project due to lack of endorsement from the creators, with $1 million pledged at the time it was shut down.[112]

Joss Whedon, Tim Minear, and cast members Nathan Fillion, Alan Tudyk, Summer Glau, Adam Baldwin and Sean Maher reunited at the 2012 San Diego Comic-Con for a 10th anniversary panel. Ten thousand people lined up to get into the panel, and the panel ended with the entire crowd giving the cast and crew a standing ovation.[113]

A tenth anniversary special, Browncoats Unite, was shown on the Science Channel on November 11, 2012. The special featured Whedon, Minear, and several of the cast members, in a discussion on the series' history.[114]

According to Reason's Julian Sanchez, Firefly's cult following "seems to include a disproportionate number of libertarians." The story themes are often cautionary about too-powerful central authority and its capacity to do bad while being considered by the majority as good. The characters each exhibit traits that exemplify core libertarian values, such as the right to bear arms (Jayne, Zoe), legal prostitution (Inara), freedom of religion (Book), logic and reasoning (Simon), and anti-conscription (River).[115] Joss Whedon notes this theme, saying "Mal is, if not a Republican, certainly a libertarian, he's certainly a less-government kinda guy. He's the opposite of me in many ways."[116]

On the CBS sitcom, The Big Bang Theory, Sheldon Cooper is a fan of Firefly. When he and Leonard Hofstadter are discussing their roommate agreement, they include a passage in which they dedicate Friday nights to watching Firefly, as Sheldon believes it will last for years. Upon its cancellation, he brands Rupert Murdoch, the owner of Fox, a traitor.[118] During the second season of The Big Bang Theory, in episode 17 ("The Terminator Decoupling"), Summer Glau appears as herself, encountering Sheldon, Leonard, and their friends on a train to San Francisco. When Raj tries to hit on her he says that although he is an astrophysicist, she was actually in space during the shooting of Firefly. Glau chides him for believing this and Raj backtracks, saying, "Those are crazy people!"[119]

On the NBC comedy Community, the characters Troy and Abed are fans of the show. They have an agreement that if one of them dies, the other will stage it to look like a suicide caused by the cancellation of Firefly, in the hopes that it will bring the show back.[120]

In the 2003 Battlestar Galactica miniseries/pilot, a ship resembling Serenity appears in the background of the scene with Laura Roslin (Mary McDonnell).[121]Serenity is one of several spaceships inserted as cameos into digital effects scenes by Zoic Studios, the company responsible for digital effects in both Firefly and Battlestar Galactica.[121]

The television series Castle, where Fillion plays the lead character Richard Castle, has made ongoing homages to Firefly. Castle has props from Firefly as decorative items in his home, has dressed up as a "space cowboy" for Halloween ("You wore that five years ago," cracked his daughter), speaks Chinese that he learned from "a TV show [he] loved", and has made rapid "two-by-two" finger motions while wearing blue surgical gloves. He has been humorously asked if he has ever heard of a spa known as "Serenity", and Firefly catchphrases such as "shiny", "special hell", and "I was aiming for the head" have been used as punchlines during various dramatic scenes in Castle. He has worked a murder case at a science fiction convention with suspects being the cast of a long-cancelled space opera that only ran for a season, and has had incidental interaction with people portrayed by Firefly cast members.[122][123][124]

Con Man, a 2015 comedy web series created by Tudyk and co-produced by Fillion, draws on the pair's experiences as cult science fiction actors touring the convention circuit.[125][126] Though it is not autobiographical, the show's fictional Spectrum echoes Firefly and Tudyk's and Fillion's roles reflect their own Firefly roles. Staite, Torres and Maher made guest appearances. Maher played himself as a former Firefly actor.[126][127][128]

The popularity of the short-lived series served as the launching point for a media franchise within the Firefly universe, including the feature film Serenity, which addresses many plot points left unresolved by the series' cancellation.

Additionally, there are two comic-book mini-series, Serenity: Those Left Behind (3 issues, 104 pages, 2006), Serenity: Better Days (3 issues, 80 pages, 2008) and a one-shot hardcover Serenity: The Shepherd's Tale (56 pages, 2010), along with the one-shots Serenity: Downtime and The Other Half and Serenity: Float Out in which Whedon explored plot strands he had intended to explore further in the series. The comics are set, in plot terms, between the end of the TV series and the opening of the feature film. The two mini-series were later published in collected form as hardcover and paperback graphic novels. A six-issue series titled Serenity: Leaves on the Wind began in January 2014 and the series takes place after the events of the film.[129] A six-issue series titled Serenity: No Power in the 'Verse began in October 2016 and the series is set about 1.5 years after Leaves on the Wind.[130] In July 2018, Boom! Studios announced that they had acquired the comic book and graphic novel publishing license to Firefly with plans to release new monthly comic book series, limited series, original graphic novels and more.[131]

In July 2014, the release of video game Firefly Online was announced that planned to have the cast reprise their roles.[132]